Time-domain dynamic drift optimisation of tall buildings subject to stochastic wind excitation

Abstract

Wind-resistant design of tall buildings has been traditionally treated using the equivalent static load approach. In order to account for the uncertainties in random wind excitation, it is necessary to develop a comprehensive and reliable dynamic optimisation technique in the time domain. The optimal lateral stiffness design problem of wind-excited tall buildings consists of (1) identifying the critical dynamic drift response in the time domain and (2) searching for the optimal distribution of element stiffness of the building subject to multiple drift design constraints. The critical time-history drift constraints of a wind-excited building are first treated by the worst-case formulation and then explicitly expressed in terms of element sizing variables using the principle of virtual work. The extreme value distribution and the Gaussian assumption are employed to formulate and simplify the probabilistic drift constraints, which are explicitly considered in the dynamic optimisation problem. The system reliability associated with the interstory drift is estimated approximately by the bound approach to ensure that the most cost-efficient solution also attains an acceptable reliability level. A full-scale 45-story building example under wind tunnel derived time history wind loading is presented to illustrate the effectiveness and practicality of the reliability-based dynamic optimisation technique.

Keywords::

• time history analysis
• dynamic response optimisation
• reliability
• peak factor
• tall buildings

Funding

The work described in this paper was partially supported by the National Natural Science Foundation of China [grant number 51008275]; Ministry of transport of P.R. China [grant number 2011318223170]; Scientific Plan Project of Zhejiang Province of China [grant number 2012C21059] and the Fundamental Research Funds for the Central Universities of China [grant number 2012QNA4013].

Notes

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^3. Email: [email protected]